Place all filling ingredients into a bowl and mix together until well combined. Set aside.
Brush perimeter of a wonton wrapper with the beaten egg and fill center with 1 heaping tablespoon of pork filling.
Open your dominant hand, palm side up, and hold fingers together.
Place the filled and open wonton wrapper onto your fingers and fold the wrapper in half, only sealing the corner of one side.
Using your other hand, push small pleats onto one side of the wrapper, pressing and sealing with the hand holding the potsticker.
Set aside and repeat until all filling and wrappers have been used.
Heat a large, heavy bottom skillet over medium heat and add 2 tablespoons oil.
Add 5 to 6 pot stickers to skillet, so the crimped side is up, and pan-fry for 3 to 4 minutes.
Add about 3 tablespoons water to the pan and cover for 2 to 4 minute or until the wonton wrappers have softened and steamed and the filling has finished cooking through.
Remove from heat and repeat until all potstickers have been cooked. Serve immediately with dipping sauce.
Choganjang: Place all ingredients into a small bowl and whisk together. Serve with potstickers.